/*public class Test {
    public static void main(String[] args) {
       *//* Rectangle rect = new Rectangle();
        Circle circle = new Circle();
        Traingle traingle = new Traingle();

        Shape[] shapes = {rect, circle, traingle};
        for (int i = 0; i < shapes.length; i++) {
            shapes[i].draw();
        }

        System.out.println("========");

        for (Shape s : shapes) {
            s.draw();
        }*//*
        //Traingle t = new Traingle();
        Tools t = new Tools();
    }
}*/


class B {
    public int Func() {
        System.out.print("B");
        return 0;
    }
}
class D extends B {
    @Override
    public int Func() {
        System.out.print("D");
        return 0;
    }
}
public class Test {
    public static void main(String[] args) {
        B a = new B();
        B b = new D();
        a.Func();
        b.Func();
    }
}